In June 1918, Derbyshire and her colleague Gerald Kneale investigated alleged hauntings (actually time shifts from the future) at St Teilo's Hospital in Cardiff. They escorted Tommy Brockless out of his ward to ensure his cryogenic freezing and returned the "future" Tommy to his native time to ensure history would take its proper course. (TV: To the Last Man)
Behind the scenes
The full version of the photograph seen in the episode was released by the production team.
The series 2 version of the Torchwood website had a profile of 1918 Torchwood Three operatives, including Harriet. It said that in her time period, though women could attend lectures and sit examinations, they could not take degrees. Harriet sat in physics lectures at the University of Oxford, educating herself in the subject "for years". Recognising her aptitude, a professor at the University recommended her to Torchwood. Prior to her death in 1919, she was making notes for a paper that would have "beaten Heisenberg to the Uncertainty Principle". When Oxford changed its regulations in 1920, Harriet was given a posthumous degree.